Subj : Re: WWV Solar Report
To : Craig Healy
From : Holger Granholm
Date : Fri Mar 30 2001 12:34 pm
In a message dated 03-29-01, Craig Healy said to Holger Granholm:
-> Quite unreliable forecast in my opinion.
CH>This question has come up in the past. The best answer I've seen is
CH>that local conditions may vary markedly.
Hello Craig,
Thanks for your reply but I beg to differ as far as aurora goes.
I have been a ham since 1951 and worked on VHF and up since 1960's.
CH>The ionosphere is not a uniform layer, but has large local variations.
CH>What might be perfectly valid for the actual forecast location may be
CH>quite different some thousands of kilometers away.
Correct as far as tropo and sporadic-e conditions are concerned.
A very simple explanation of how an aurora is born follows:
The aurora is created by particles thrown out from an eruption on the
suns surface, a solar flare. When the particles (electrons) reach the
auroral zone the aurora is created.
The auroral zone covers the entire northern hemisphere around the north
pole which is of interest to us living north of the equator.
Local variations have very little to do with aurora but how far south
you are situated from the north pole is of greater importance.
Of course chances are minimal that you'll experience a radio aurora in
for example Texas but the detrimental effect on shortwave conditions
will be very marked even there.
A more complete description though not complete may be found in the
ARRL Radio Amateurs Handbook, chapter 22 in my old version.
However, I don't suggest that the solar reports be removed as unreliable
because I think that they and the weekly bulltins keep the echo alive.
